1. Field of the Invention.
The present invention relates to machines for husking corn, and in particular to husking roll sections which may be used for husking sweet corn and seed corn.
2. Description of the Prior Art.
When husking any kind of corn, several goals should be achieved. First, the husks should be removed from a high percentage of the ears of corn. Second, any attached stalks also should be removed from the ears. Third, the shelling of kernels of corn from the cobs should be kept to a minimum. Seed corn is generally harvested when it is relatively dry, and therefore it tends to shell more easily than sweet corn, which is supple. Reducing shelling to a minimum with seed corn is particularly important, because seed corn is a relatively expensive commodity. Another important goal in husking seed corn is maintaining a high rate of germination. Sometimes the rough action of removing the husks from an ear can scrape or otherwise damage the individual kernels of seed corn, thereby greatly increasing the danger that they will not germinate.
The prior art is generally cognizant of various types of rolls which are used in stripping and husking corn and destemming other articles of produce. Sweet corn is generally picked in the field without the husks being removed. After picking, the ears of corn are then taken to a plant where they are placed in a corn husker which husks the corn and removes any attached stalks, hopefully with little damage to the tender kernels. On the other hand, seed corn often has been husked using a two-step system. The seed corn is husked once on the picker, and then husked a second time at a station. More recently, however, it has been found that seed corn can be husked more efficiently using a one-step husking procedure, whereby the seed corn is first husked at the station in a corn husking machine.
Metal rolls have been used in corn harvesters which both pick and husk the corn, and also in corn huskers. Rubber rolls also have been used in both types of machines. Metal rolls tend to remove husks less aggressively than rubber rolls, and therefore, cause lower shelling losses of kernels. However, the use of metal rolls alone often leaves too many ears which have not been husked completely. Longitudinal blades or ribs have been used on metal rolls to cut and eject stalks away from the ears being husked. This type of longitudinal blade is shown in U.S. Pat. No. 135,841 to Philip, U.S. Pat. No. 2,489,495 to Morral et al., U.S. Pat. No. 2,905,181 to Nelson, and U.S. Pat. No. 4,625,735 to Anderson et al. These longitudinal blades have exposed sharp edges which may cause damage to the kernels.
To obtain a more aggressive removal of husks from ears of corn, rolls formed from resilient materials such as rubber are often used. Aggressive rubber rolls are generally quite beneficial for use in husking ears of sweet corn, since the kernels are supple and therefore resistant to shelling. However, such rubber rolls, especially those having standard high-profile lands and grooves, can be too aggressive for husking seed corn. The dry, brittle kernels in seed corn are easily agitated loose by the aggressive action of such rubber rolls. This aggressive action also often causes damage to the individual seed kernels, thereby reducing their chances of germination.
Another problem may occur when two cooperating counter-rotating rubber rolls are used to husk corn. Sometimes a connected corn stalk will get caught between the two rubber rolls causing the stalk to move into an upright position. The rubber rolls are often unable to break the stalk off from the ear, so the stalk remains wedged between the two rubber rolls. Since the rolls are made from rubber, as the rolls rotate, an annular groove may form in the rolls where the stalk is caught. Such a groove reduces the effectiveness of the rolls, which must then be replaced at substantial cost and loss of time. This can particularly be a problem with seed corn, which usually has a large number of stalks attached to the ears to be husked.
The use of rubber husking roll sections having lands and grooves therebetween is old in the art, and is shown, for example, in U.S. Pat. No. 3,113,574 to Greedy et al. and U.S. Pat. No. 2,535,485 to Cover, the disclosures of which are hereby incorporated by reference. Cover and Anderson, et al. disclose using resilient husking roll sections interposed on a shaft between non-resilient companion elements.